Dyeing of elastic fabrics



July 6, 1937. A. lsAAc' DYEING oF ELASTIG FABRICS Filed June 5, 1955 3Sheets-Sheet 1 IIIIIIGI llllllll Il JIZ July 6, 1937. A. lsAAc "DYEEINGoF ELASTIG FABRICS 3 Sheets-Sheet 2 Filed June 5, 1935 July e, .1937. A.ISAAC 2,086,298

DYEING oF ELASTIC FABRICS i Filed June 5, 1955 3 Sheets-Sheet 5 PatentedJuly 6, i937 acetate I nannies oir nnas'rrc nannies Augustin lisaac,lLyon, France, assigner to Dognin, Societe Anonyme, Villeurbanne,France, a company of France Application .lune 5, 1935, Serial No. 25,144

. lin France `lune l2, 193e .It is known that elastic fabrics made withmade, as well in the longitudinal asin the transthreads of rubber or asimilar material which is verse direction, by comparing the number ofspecifically elastic are very difcult to dye in an meshes when thefabric is not elongated and even manner. This dimculty is due to theinwhen itis elongated.

timate contact existing between the rubber Another feature of theinvention consists in Y threads and the weft threads, which contactcoupling together, through any suitable trans-v prevents the dye fromfully impregnating the mission such as a chain or a pinion transmission,textiles, especially at the places where the the two cylinders of thetransverse stretcher threads cross one another. Y bars in order to avoidthe phenomena. of periodical 'I'he chief object of the present inventionis increase and decrease of the tension during the 10 to obviate thisdrawback. For this purpose I dyeing operation. have provided .a processcharacterized in that, Another feature of the invention consists induring the dyeing operation, the fabric is not providing means, adaptedto act in the course of only stretched in the direction of its width, inthe dyeing process, for evening the intensity of the usual fashion, butalso subjected to a subdyeing across the width of the piece of fabric,15 stantial elongation, either in the longitudinal or l in such mannerthat the shade should not be in the transverse direction, or eventuallyin both deeper along the edges than in the central part of thesedirections. In this manner, the volurne of the piece. For this purpose Imay provide of the rubberthreads, when they are elongated,` means f01`Performing a supplementary Sprindecreases so that these threads cease tobe in klingof the central partv of the piece of fabric 20 intimatecontact with the other threads of the that is to say of the part o fsaid piece extending fabric. Therefore said fabric can be fully imfromthe median line thereof to a certain dispregnated by the dye in which itis immersed. tance from the edges. I may also, according to' Otherfeatures of the invention relate to the the invention, provide therollers on which the application of the process above mentioned byfabric is wound up with suitable cheeks or side 25 means of dyeingapparatus of the Well known plates Which Prevent direct lateral Contactbejigger type. The elongation of -the fabric is tween the mass of fabricwound up on the roller obtained by exerting on the roll of fabricthat'is and the surrounding space. I'lnay e180, Still ee'- being unwounda strong braking action sumcording to the invention, provide means forexcient in order that, through elastic deformaertingacomplementarycompression on the mar- 30 tion, the portion of the fabric that passesginal edge 0f the fabric, these Ineens including, through the dyeing vatmay be elongated to an for instance, two smalllateral compressingmemamount ranging between 15% and 100% and bers, mounted on thetransverse stretcher bars even more. or on the outlet end transversestretcher bar,

Furthermore, the rollers on which the fabric these members beingarranged to compress the 35 is wound up and from which it is unwound aremarginal DOlliOnS 0f the T011 0f fabricprovided with brake drums havingfree wheel de- Still another feature of the present invention vicesacting in opposite directions, so that each consists in controlling thewinding up of the of the rollers, which acts alternately for windfabricon the corresponding roller in such moning up the fabric and forunwinding it, can be ner that its Width may remain uniform. For 40braked when it is acting -for unwinding the this purpose, the action ofthe transverse fabric, while the other roller is not brakes andstretcher bars is regulated in a suitablemarmer, is imperatively causedto rotate, this result beby varying, for instance manually, the angularing obtained without removing the braking position of the transversestretcher bar or of a weights. portion of said bar. 45

Finally, the curved guiding, or transverse Other features of the presentinvention will stretcher, bar may be provided with a miororesult fromthe following detailed description of metric device for adjusting itsangular position in some specific embodiments thereof. Y such manner asto permit of adjusting the Preferred embodiments of the presentinvention stretching in the transverse direction. Furtherwill behereinafter described; with reference t0 50 more, bars provided withclips may eventually the accompanying drawings, given merely by way beutilized when the elongation in the transof example, and in which:

verse direction is to be very important, for in- Fig. 1 is adiagrammatic vertical sectional view stance greater than 30%. of ajigger apparatus modified according to the The measurement of theelongation can be presentinvention; 5

Fig. 2 is a diagrammatic plan view corresponding to Fig. 1;

Figs. 3 and 4 are detail views illustrating the arrangement of the freewheel devices mounted on the rollers on which the fabric is wound up andunwound Fig. 5 is a sectional view on the line 5 5 of Fig. 4;

Fig. 6 is a detail view, on an enlarged scale, of aportion of theapparatus of Fig. 1, showing the curved transversestretcher bar;

Fig. '7 is a plan view corresponding to Fig. 6;

Fig. 8 is a diagrammatic detail view showing the shape of the transversestretcher bar;

Fig. 9 is a vertical sectional view of another embodiment of theapparatus of Fig. 1;

Fig. 10 is a perspective view showing a device for compressing themarginalportion of the roll of fabric;

Fig. 1-1 is a vertical transverse section of the device of Fig, 10;

Fig. 12 is a side elevational View of a device permitting of regulatingmanually the angular position of the transverse stretcher bar;

Fig. 13 is a plan view corresponding to Fig. 12;

Fig. 14 shows a modification corresponding to the case of a transversestretcher bar made of two halves adjustable with respect to each other.

In the embodiment shown in Figs. 1 and 2, the jigger apparatus includesa vat a containing the dyeing bath and in which passes the fabric bwhich is unwound from a roller d and wound upon a roller c. Each ofthese rollers serves, alternately to the winding up of the fabric andthen to the unwinding thereof. T'hese rollers are driven through atransmission shaft m which can be coupled,through a clutch p, witheither of two bevel pinions An and o, as shown by Fig. 2.

On the vat or tank is mounted the oscillating frame e at the ends ofwhich the transverse stretcher bars f1 f2 and the guiding rollers g1 g2are mounted. The rollers c and d which serve alternately to the Windingup and the unwinding of the fabric are keyed on shafts c1, d1,respectively. These shafts are adapted to Ibe braked through drums c2,d2 subjected to the action of braking bands h, i carrying weights k, l,respectively, or in any other suitable manner.

A pawl and ratchet device c3, d3, or any other equivalent device actingas a. free wheel, is interposed between each of the shafts c1, d1 andthe corresponding brake drum c2, d2, but the teeth of these respectiveratchet devices are disposed in opposite directions, that is to say thefree-wheel devices act in opposite directions.

Under these conditions, the two braking devices h k and 1l Z beingconstantly in action, the free wheel devices produce a strong braking ofroller d, from which the fabric is being unwound, while leaving theroller c on which the fabric is being Wound up free to rotate, wherebythis last mentioned roller can be driven by transmission shaft m andexerts a pull on fabric b. This pull, acting against the braking actionof brake i I, produces an elongation ofthe fabric in the longitudinaldirection, by elastically deforming the threads of said fabric. Onlywhen the elongation has reached a certain amount (which depends upon theimportance of the braking action) does the fabric b move for winding upupon roller c while unwinding from roller d. V'Iherefore the fabricpasses through tank a not only stretched transversely so as to be fiat,as in the case of ordinary fabrics made of non-elastic threadsrbutin astate ci' elongation, this elongation being eventually efforts may be ashigh as 1000 kilograms andeven more.

When the whole of the fabric is wound up on a roller c, it is unwoundfroml said roller so that the fabric moves in the opposite direction,the free wheel devices automatically transferring the braking actionfrom one roller to the other one.

While the fabric is moving in the bath it is not only elongated but alsofully stretched in the transverse direction owing to bars .f1 f2.According to the present invention, it is possible to adjust theinclination of each of these bars in such manner as to bring it .out ofthe way or, on the contrary, to give it -a suitable angular position.The adjustment preferably takes place through a micrometric control, asshown in Figs. 6 and '1, by means of a screw q acting on a wheel r keyedon the spindle f about which bar f1 or f2 is pivoted.

It should be noted that when the bar is in the position shown in Fig. 6or close to this position,

it produces, because of the tension imparted to the fabric b, astretching of said fabric in the transverse direction, whereby the dyeis allowed to penetrate fully into the -fabric.

The transverse stretching bar can be replaced, once the correctadjustment has been found, by a non-cylindrical roller of analogousprofile, as shown in f3 in Fig. 8.

It is desirable, in order to dye the fabric as evenly as possible, towork with an elongation as uniform as possible. But a diiiiculty arises:The

`diameters of the rollers on which the fabric is wound up and from whichit is unwound simultaneously increase and decrease, respectively, thusvarying the resulting braking action and elongation. This diiliculty wasnot experienced in the jigger apparatus as used up to this time, becauseit was only desired to cause the fabric to pass through the bath in aregular manner, without folds. As a matter of fact, for most fabrics,special devices were used for reducing the tension of the fabric to aminimum and apparatus were devised in which this tension was practicallyeliminated. On the contrary, according to the present invention, it maybe desired'to render the braking torque as uniform as possible,automatically if possible, for instance by making use of a band brakewhich is tensioned not by a free weight but by means of a lever alongwhich said Weight can slide. The automatic displacement of this weightalong said lever can be obtained through a roller which bears constantlyupon one of the rolls of fabric and the displacements of which controlthe displacement of the weight along the lever.

In order to reduce to a minimum the necessity of this adjustment, andeven to eliminate it in some special cases, another modification to theordinary jigger apparatus shall consist in increasing the diameters ofthe rolls of fabric as much as possible, for instance by making themtwice or even thrice greater than the usual values. In this way, therelative difference of tension due to the variation in the diameters ofthe rolls will be considerably reduced, especially when the apparatus isutilized with pieces of fabric of relatively short length.

It should be well understood that, by suitably adjusting the apparatus,it is possible to utilize, according as the need may be, either combinedelongation and transverse stretching or only elongation.

By `comparing the dyed fabrics obtained ac- .esv

cording to the ordinary methods and those cbabscess tained in accordancewith the present invention by means of a jigger or any other apparatuspermitting to subject the fabric to a suitable elongation,A thefollowing is noted:

(a) the dyeing action is uniform owing to the elimination of thedifferences resulting from the non-uniform tensions of the weft on thewarp;

(b) the breaks that occur generally when dyeing heavy fabrics areeliminated;

(c) the dye penetrates in a perfect manner into the fabric;

(d) the fabric is not injured and is not displaced;

(e) the fabric is more regular and even due to the combined action ofelongation and transversev stretching of the fabric while passingthrough the dye bath at high temperature. This result is explained bythe reduction of the tensions of the rubber threads under the influenceof heat and the resetting in position of the vegetable or animal textilefibers under the influence of elongation and transverse stretching.

This last action makes it possible to obtain fabrics which are perfectlyfiat and smooth in spite of irregularities of the raw material, whilewhen no elongation is produced the finished fabric has a veryunfavorable corrugated aspect.

The rollers that are utilized in actual practice receive pieces offabric of considerable length and weight and they mustbe subjected toimportant braking efforts. Consequently they must be very strong andconsist of solid drums having a considerable inertia. When they arecharged with pieces of fabric they are capable of storing up animportant amount of energy. Taking into account the elasticity of thefabric, it will be easily understood that the following phenomenon canoccur: When the driven roller is brought into action, the fabricextending between the two rollers'is tensioned more 'than it would do ifthe working speed were obtained because the fabric must overcome notonly the resistance opposed by the brake but also the inertia of theroller that is being braked. When said roller has reached a certainspeed of revolution, the tensionv tends to decrease but it does not takethe value v it should have because the roller that is braked,

which has been started under the influence of a high tension of thefabric now feeds fabric at too high a rate. The tension of the' fabricnow drops down to an exaggeratedly low value, the speed of revolution ofthe braked roller decreases and the same phenomena again occur and maybecome periodical.

The present invention includes improvements to the machine abovedescribed for obviating the detrimental action of the inertia of therollers on the uniformity of tension of the fabric and therefore on thequality of the product.

One of these improvements consists in reducing the diameter of therollers the mass of which is, in fact, concentrated chiey in thevicinity of the rim.

Another improvement, which may be -employed either separately or incombination with the above mentioned one consists in coupling with theroller from which fabric is being unwound a governor of any kindmodifying the braking of the roller in accordance with the speed ofrevolution of said roller so as to render thisspeed as uniform aspossible.

Alternately, and eventually in combination with the first of the twoabove mentioned improvements. the two rollers may be interconnected,since one roller must receive as much fabric as there is fabric unwoundfrom the other one.

bcdiment illustrated by this figure, the pinions or sprocket wheels t1,t2 keyed on the spindles of rollers g1, gz are connected together bymeans of a chain u.

The angle made by the fabric b when passing around these rollers g1, g2is relatively small but.

still it is sumcient for giving said rollers, although their surfacesare smooth, an adhesion with the fabric sufficient for reducing thedetrimental action of the periodicity above mentioned and'eveneliminating this action, whereby the fabric is unwound in a continuousmanner at a uniform rate.

A. particularly interesting advantage of the interconnection of therollers of the transverse stretcher bars by means of a chain or theequivalent is to eliminate the undesirable polishing of the pieces ofelastic fabric. As a matter of fact, up t'o this time, the periodicvariations in the unwinding of the fabric above referred to produced notonly unevenness of the dyeing and, even in some cases, slidingdisplacements of the weft, but also friction between the successivelayers wound up around the cylinder. This friction produces on thesurface of the fabric traces similar to snail tracks. Similar traces arealso produced when the bad working of the roller produces at acertain'time the stoppage of a transverse stretcher bar roller. Thesetraces result in this case from friction of the fabric on the stoppedroller.

These drawbacks are fully obviated when the rollers are interconnected.

A well known drawback of dyeing with the jigger apparatus is the edgeeffect which consists in the fact that the edges of the fabric are dyedto a deeper shade than the remainder of said fabric.

The special texture of elastic tulle or similar fabrics, which are morepermeable to liquidsthan ordinary fabrics, accentuates this drawback. Itis therefore necessary, when dyeing elastic fabrics such as tulle ornet, to correct this defect as fully as possible.

For this purpose, I may, without trying to eliminate the causes thatproduce this deeper dyeing along the edges, compensate for this effectby reinforcing the intensity of dyeing of the central part of thefabric. This result is obtained by soaking this central part alone withthe dye bath itself, which is pumped up from the bottom of the tankthrough filtering screens.- The liquid is fed through valves provided insufficient number to nozzles distributed along the axis of theapparatusand above every roller. A

I may also, according to the present invention, try to eliminate thecause of the phenomenon by fitting to the roller, on either side of theroll of fabric wound therein. adjustable cheeks which transform. theroller into a kind of huge spool and prevent'lateral contact of the rollof fabric with the surrounding'bath and consequently any abnormalcirculation of liquid through the fabric by capillarity.

I may also, according to the presentinvention, provide means forexerting on the marginal portion oi' the roll of fabric a compressionintended to drive out the liquid that has a tendency to accumulate. insaid portion of the roll of fabric. Preferably, these means must be sodevised as to produce a compression as uniform as possible of the edgeof the roll of fabric and of a marginal portion thereof extending tosome centimeters from said edge.

Figs. 10 and 11 show an embodiment in which the compression of the edgeand marginal portion of a roll of fabric b1 is obtainedA through a bandoffrubberized fabric o1 suitably tensioned by means ofl weights q1. v

I may also apply upon this edge and marginal portion of the roll offabric a wide surface .and cause it to compress the fabric as uniformlyas possible for instance by means of' levers loaded` with weights attheir end'and working in juxtaposition. In either case it is necessaryto obtain an action of the weights the component of which toward thecenter of the mass is relatively important.

I may still adjoin to each transverse stretcher bar roller and on eitherside thereof a small compressing cylinder, applied thereon through anysuitable means. These two lateral cylinders shall compress the marginalportions of the fabric over a distance sufficient for obtaining thedesired result.

The edge effect above described is complicated, in the case of fabricsthat are extensible in the transverse direction, by the fact that theedges are not evenly dyed. 'I'his defect is due to the fact that, duringthe winding of the fabric, its width does not remain uniform. 'I'hisdefect may, in somecases, be still more important than the edge effectproper. In order to obviate this drawback, the action of the transversestretcher bars f1, f2 is controlled through means permitting tol vary itinstantaneously by modifying the angular position of said bars.

For this purpose, as shown in Figs. 12 and 13, the' end of each bar,such as f1, is provided with a lever s1 provided with means s2 forfixing it in any desired angular position about the axis of f1. It willbe readily understood that, by displacing this lever the inclination ofthe bar and therefore the action thereof can be modified at will.

In the embodiment shown by Fig. 14, the bar is made of two halves, such.as f, adapted to turn independently about a central support v. To theend of each portion i of the bar there is xed a lever so arranged inthe'same manner as lever s1 so as to permit of varying the inclinationof each portion of the bar and of obtaining a perfect adjustment of theaction on the respective edges of the fabric. This arrangement alsopermits of remedying the tendency of the fabric to move as a wholetoward the right hand side .or the left hand side.

While I have, in the labove description, disclosed what I deem to bepractical and eiiicient embodiments of the present invention, it shouldof the present invention as comprehended within the scope ofthe appendedclaims.

What I claim is:

1. A methodof dyeing elastic fabrics which comprises stretching thefabric by an amount at least equal to 15 per cent while passing itthrough the dye bath.

2. A method of dyeing elastic fabrics, which comprises elongating thefabric in the longitudinal direction while passing it through a dyeingbath, the amount of elongation being at least equal, to 15 r cent. 3. Ame od of dyeing elastic fabrics, which comprises elongating the fabricin the transverse direction, while passing it through a dyelngbath, theamount of elongation being at least equal to 15 per cent.

4. A method of dyeing elastic fabrics, which comprises elongating thevfabric both in the longitudinal direction and in the transversedirection, while passing it through a dyeing bath, the amount ofelongation in each of said directions being at least equal to 15 perlcent.

5, A method of dyeing elastic fabrics having rubber threads disposedtherein, which method comprises elongating said fabric in the directionof said rubber threads by4 an amount at least equal to 15 per cent,while simultaneously passing said fabric in operative contact withdyeing material.-

6. A method of dyeing elastic fabrics includ ing a set of rubber threadsdisposed in contacting relation with a set of other threads, one of thesets being at least a part ci' the weft while the other set is yat leasta part of the warp of said fabric, which method comprises stretchingsaid fabric in the direction of the rubber threads for elongating thelatter to such an extent that the cross-section of said rubber threadsissubstantially reduced, thus reducing the contact between 'the sets ofthreads, while simultaneously passing said fabric in operative contactwith dyeing material.-

7. A method of dyeing elastic fabrics including a set of rubber threads.and at least one furtherl set of threads which individually form tightloops about said rubber threads so as to be in close contact therewith,which methodcomprises stretching said fabric in the direction of therubber threads for elongating the latter, to such an extent as torelieve the loops from contact with said rubber threads, whilesimultaneously passing said fabric in operative contact with dyeingmaterial.

v8. A continuous method of dyeing lengths of elastic fabric havinglongitudinally disposed rubber threads, which comprises feeding saidlength into andpast an inlet nip then into and past a remote outlet nip,elongating said length between said inlet nip and said outlet nip by anamount at least equal to 15 per cent, while simultaneously passing saidlength between the nips in operative contact with dyeing material, and

positively synchronizing the rates of feed through said inlet nip and`outlet nip respectively.

9. The method of claim 8, further comprising spreading said length offabric in the transverse direction while passing the 'same in operativecontact with the dyeing material.

AUGUSTIN ISAAC.

